#ifndef BASE_BASE64_H_
#define BASE_BASE64_H_

#include <string>

namespace MSF
{
  static const std::string chars =
    "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
    "abcdefghijklmnopqrstuvwxyz"
    "0123456789+/";

  static inline bool is_base64(unsigned char c) {
    return (::isalnum(c) || (c == '+') || (c == '/'));
  }

  inline std::string encode(unsigned char const* bytes_to_encode, size_t in_len) {
    std::string ret;
    int i = 0;
    int j = 0;
    unsigned char char_array_3[3];
    unsigned char char_array_4[4];

    while (in_len--) {
      char_array_3[i++] = *(bytes_to_encode++);
      if (i == 3) {
        char_array_4[0] = static_cast<unsigned char>((char_array_3[0] & 0xfc) >> 2);
        char_array_4[1] = static_cast<unsigned char>( ( ( char_array_3[0] & 0x03 ) << 4 ) + ( ( char_array_3[1] & 0xf0 ) >> 4 ) );
        char_array_4[2] = static_cast<unsigned char>( ( ( char_array_3[1] & 0x0f ) << 2 ) + ( ( char_array_3[2] & 0xc0 ) >> 6 ) );
        char_array_4[3] = static_cast<unsigned char>( char_array_3[2] & 0x3f );

        for(i = 0; (i <4) ; i++)
          ret += chars[char_array_4[i]];
        i = 0;
      }
    }

    if (i)
    {
      for(j = i; j < 3; j++)
        char_array_3[j] = '\0';

      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
      char_array_4[3] = char_array_3[2] & 0x3f;

      for (j = 0; (j < i + 1); j++)
        ret += chars[char_array_4[j]];

      while((i++ < 3))
        ret += '=';
    }

    return ret;
  }

  inline std::string decode(std::string const& encoded_string) {
    size_t in_len = encoded_string.size();
    size_t i = 0;
    size_t j = 0;
    int in_ = 0;
    unsigned char char_array_4[4], char_array_3[3];
    std::string ret;

    while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
      char_array_4[i++] = encoded_string[in_]; in_++;
      if (i ==4) {
        for (i = 0; i <4; i++)
          char_array_4[i] = static_cast<unsigned char>(chars.find( char_array_4[i] ));

        char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
        char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
        char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

        for (i = 0; (i < 3); i++)
          ret += char_array_3[i];
        i = 0;
      }
    }

    if (i) {
      for (j = i; j <4; j++)
        char_array_4[j] = 0;

      for (j = 0; j <4; j++)
        char_array_4[j] = static_cast<unsigned char>(chars.find( char_array_4[j] ));

      char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
      char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
      char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

      for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
    }

    return ret;
  }
} // namespace MSF

#endif // BASE_BASE64_H_